First relationship

Hey Ladies! So as you guessed I'm sure, I'm in my first real relationship and have been having a lot of stress and anxiety surrounding it. I'm not totally sure where it's coming from but think I have an idea.

At 20 years old I got into my first real relationship with a long time friend he was 25 at the time. We have been together for 7 months. I'm now 21 and he's now 26. I say my first real relationship because I only dated two other guys and that was in grade school so nothing serious. So anyways back to the topic of the story... I have been having a lot of stress and anxiety surrounding our relationship and for months now I've been trying to figure it out. I think I figured it out and tell him about it so we can work it out and my stress and anxiety only got worse.

I told him what I believe was bothering me but knew he wouldn't want to talk about it so told him we did not have to I just need him to know how I have been feeling. He of course as expected had no interest in talking about it and I'm fine with that but I'm afraid it's eating away at me in a manner of speaking because my anxiety has been much worse since telling him what I believe was bothering me.

What I believe is bothering me...

He has been my first for everything relationship, sex, love etc. He however has been in other relationships and they were never good. He was cheated on and lied to in every relationship and I know the girl he was with before me for 2 and a half years was mentally and physically abusive to him and he was single for almost 2 years before we started dating. Because of his rocky past with relationships he refuses to talk about them which is fine I respect that but he has broken down in tears a couple of times to me and mentioned a few vague things about some of the relationships he's been in which only made me want to know more. He regrets all of his relationship before me. I know I'm the 7th girl he's been with sexuality because he did tell me that and I think I'm jealous or insecure of that. I believe my stress and anxiety was over the fact I don't know who he's had sex with before me, knowing he's the only one I've been with. I told him this so he would know how I was feeling but made sure he knew he did not have to tell me who he's been with before me as I know it's none of business if he doesn't want to share that with me and we left it at that. Ever since we had that conversation my anxiety has been through the roof and I don't know what to do!! Now I'm questioning... was that really what was bothering me or is it something else?

I am however someone who believes if you're having sexual relations with someone and they want to know about your sexual history you should share that with them because I believe when you have sex with someone you are not only having sex with them but everyone they have had sex with and so on in a manner of speaking... but I would never make someone tell me if they didn't want to. I've only brought it up once to him because I know he doesn't want to talk about it but needed him to know how I feel. Now I wish I didn't say anything and want to hide away.